RE: Why you video?
In my case, I found I loved sharing my stories, and when you have a camera in the tree you can capture some cool stuff - forever!
Also, I think for many guys, it just adds a new element to the hunt. Up's the challenge, regardless of what you hunting! It's also pretty cool to be able to share a hunt with a buddy in the field. Something I never realized was SOOO cool until I started hunting with a cameraman!